An efficient joint user and antenna selection for MIMO broadcast communications using Generalized Zero Forcing precoder

Generalized Zero Forcing (GZF) will be used in emerging commercial systems for Multi-User MIMO (MU-MIMO) broadcast communications. In this paper, the user scheduling problem related to it is studied. Instead of using Singular Value Decomposition based Block Diagonalization (SVD-BD) method, we construct the GZF precoder that optimally solves the Sum Rate Maximizing (SRMax) problem by a product of a channel pseudo inverse matrix and a block diagonal matrix. Later a Suboptimal User Scheduling (SUS) algorithm with Receive Antenna Selection (RAS) is designed by using a greedy user and antenna selection under SRMax and other simplified criteria. As the channel pseudo inverse can be sequentially calculated, the proposed algorithm is computationally efficient. It also achieves higher average sum rate which is verified by numerical simulations.